Answer: It is important to wet the filter paper in the Buchner funnel first with cold re crystallization solvent before the re crystallization mixture being filtered to minimize gaps around the edges of the filter paper which can prevent mechanical impurities from passing through. This gives better filtration where most impurities can be filtered. Furthermore, it provides good vacuum.
355 volcanoes in the Philippines are inactive.
24 volcanoes are active
Answer: 
Explanation:
Molecular formula is the chemical formula which depicts the actual number of atoms of each element present in the compound.
Empirical formula is the simplest chemical formula which depicts the whole number of atoms of each element present in the compound.
The empirical formula is 
The empirical weight of
= 1(12)+1(1)+1(16)= 29 g.
The molecular weight = 60 g/mole
Now we have to calculate the molecular formula:

The molecular formula will be=
Thus molecular formula will be 
The relative formua for Potassium bromide is Kbr